A method for managing data recorded in a portable device such as a MP3 player, a PDA, a handheld PC, a mobile communication device, etc, generally, includes a method of synchronizing data or files between a personal computer (PC) and the portable device. This method includes a method of connecting the personal computer to the portable device by using a wired method such as a serial port which is called as cradle synchronization, a universal serial bus (USB) port, etc, or a method of connecting the personal computer to the portable device by using a wireless method such as an infrared port, Wi-Fi, etc. Also, as for a method of transmitting data to the portable device, there is currently widely used a USB mass storage method that recognizes the portable device connected through the universal serial bus (USB) or the like in a computer as one mass storage and transmits a file or data freely. It is apparent to those skilled in the art that transmission of files or data using this USB mass storage method transmits only files or data simply, wherein there is not supported algorithm that can secure the transmitted file or data, or can protect digital rights thereof.
Various methods are being conceived to protect an owners copyright. There is growing understanding that digital contents itself is a copyright and should be protected. With this, it is also true that users who used to consider digital contents as free of charge start to change their attitudes. Methods of protecting digital contents rights are suggested as below.
A digital rights management (hereinafter, DRM) system is suggested as one method for protecting digital contents rights. This DRM system is a kind of technology embodying a system which safely transmits various contents of a network from a contents provider (CP) to a client and prevents the client from distributing the contents illegally. An encrypting technique is most important in the DRM system. This technique encrypts/decrypts digital contents using a client's password or computer ID number as key data. Therefore, although the digital contents are copied unauthorized and distributed to the third person, he/she may use the digital contents only with the key data. A method of using this key data may include 1) a method of transforming a client's computer ID or 2) a method of using a client's public key infrastructure (PKI) key or a personal key cache.
FIG. 1 is a drawing illustrating configuration of a system for embodying a method for digital contents protection according to the prior art.
FIG. 1 is one example of a digital contents providing system using DRM. DRM center 120 links digital contents providing server 110 with payment gateway system 130 and provides copyright-protected digital contents to user 140 after encrypting the same. When user 140 requests use of digital contents such as image, audio, video, etc through a network like Internet and pays predetermined fee, DRM center 120 provides the digital contents to user 140 after encrypting the same according to predetermined algorithm. Recently, disclosed is tempering that restores a source code of digital contents by using an execute-file that is encrypted and transmitted to a user. Accordingly, DRM center 120 requires a technique for efficiently preventing a hacking technique like the tampering.
Like above, although various technologies are being developed for protecting various digital contents rights on Internet, the technologies are digital right protection methods that are performed by contents providers. Therefore, it is difficult to integrate and operate the technologies as one standard among various contents providers. In addition, an owner of digital contents may have his/her right infringed unjustly because digital right protection is weakened due to various methods such as the aforementioned tempering technique or the like.
Furthermore, the conventional method of protecting digital contents right uses a respectively different method for each contents providing system. Therefore, a plurality of decryption modules may be mounted on a portable device in order to play digital contents which are encrypted in various formats. On the contrary, if the number of decryption modules is limited to be mounted on the portable device, the number of digital contents which is unplayable may increase.
Furthermore, if the number of contents providing systems increases, a user may remember user IDs and passwords as many as the number of contents providing systems in order to use the digital contents.
In order to solve the aforementioned problems in the prior art, there has been strong desire for solution which not only can support digital contents, but also can manage channels of synchronizing data between a plurality of contents providing systems, wherein the digital contents is encrypted in various formats for using contents that requires digital right protection.